Biull Eksp Biol Med. 1983 Jul; 96(7): 14-6.
[Changes in the bioelectric activity in the orbitofrontal and somatosensory areas of the cerebral cortex caused by electroacupuncture]
Effects of electroacupuncture (EAP) and intravenous injection of morphine (5 mg/kg) on evoked potentials (EP) elicited in the second somatosensory (S2) and orbitofrontal areas of the brain cortex by nociceptive (the pulp of the upper canine) and non-nociceptive (the upper lip) stimulation were studied in acute experiments on cats. After EAP the EP elicited by nociceptive stimulation of the S2 and orbital gyrus were inhibited 75 and 58%, respectively, with reference to the control level, whereas the EP elicited by non-nociceptive stimulation of the S2 and orbital gyrus rose by 30 and 45%, respectively. Morphine injection produced the same effect on the EP: an increase in the EP during non-nociceptive stimulation and inhibition during nociceptive stimulation. It is suggested that by stimulating the release of endogenous opiates and other neurotransmitters EAP remodels the function of the CNS afferent systems, facilitating the transmission of the non-nociceptive signal through the rapid-conducting lemniscal system, thereby blocking the transmission of the nociceptive signals in the multi-synaptic extralemniscal system.